Once you get used to those 2 extra buttons on the side of the Advent A6BWRD19 Optical Mouse, you won't ever want to go back to a standard mouse. Press backward & forward with your thumb for super-fast internet browsing. & what about the 6th button, you ask? That one is for adjusting the mouse sensitivity anytime you want. It's especially handy when you're sharing your PC with someone who prefers a slower or faster mouse. The ergonomic design of the A6BWRD19 Mouse makes this little guy fit right into the palm of your h&. & the rubber pads on the sides provide a firm, comfortable grip.